1. Field of the Invention
The present invention relates to a gaze direction measuring method for measuring a gaze direction, i.e., into which direction (degrees) a person captured in an image looks and a gaze direction measuring device for executing the method and in particular, to a technique which can effectively be applied to a vertical direction measuring method.
2. Description of the Related Art
By measuring a gaze direction of a person in an image, it is possible to estimate his/her object of interest and psychological state. As a method for measuring a gaze direction of a person, there has been a method for separately measuring a face direction and an eye direction and synthesizing them so as to measure a gaze direction as described in JP-A-2007-6427. This Patent Document discloses a method for measuring a face direction and a gaze direction without requiring a calibration in advance but does not disclose any method concerning the vertical direction.
There has also been a method for measuring a horizontal and a vertical direction of a face by projecting a 3-dimensional model of an object to a characteristic position such as an eye and a mouth as described in JP-A-2006-227739.